We review the paradigm of holographic dark energy (HDE), which arises from a theoretical
attempt of applying the holographic principle (HP) to the dark energy (DE) problem. Making …

A bstract A quantum extremal island suggests that a region of spacetime is encoded in the
quantum state of another system, like the encoding of the black hole interior in Hawking …

We show that the entropy of cosmological perturbations originating as quantum vacuum
fluctuations in the very early universe, including the contribution of the leading nonlinear …

We review the theoretical aspects of holographic dark energy (HDE) in this paper. Making
use of the holographic principle (HP) and the dimensional analysis, we derive the core …

A bstract According to static patch holography, de Sitter space admits a unitary quantum
description in terms of a dual theory living on the stretched horizon, that is a timelike surface …

We investigate the proposed connection between de Sitter spacetime and the multiscale
entanglement renormalization ansatz (MERA) tensor network, and ask what can be learned …

We consider the emergence from quantum entanglement of spacetime geometry in a bulk
region. For certain classes of quantum states in an appropriately factorized Hilbert space, a …

Recent developments in anti–de Sitter holography point towards the association of an
infinite class of covariant objects, the simplest one being codimension-one extremal …

We discuss a no-boundary proposal for a subregion of the universe. In the classical
approximation, this density matrix involves finding a specific classical solution of the …

A bstract We investigate observables within the framework of the codimension-one C=
Anything (CAny) proposal for Schwarzschild-de Sitter (SdS) space under the influence of …